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GREENLAND REPORT (1)
I have been intending to do a post on Greenland for some time. This is a vitally important part of the Arctic region and contains a high proportion of the permanent land ice in the Arctic. Some of the news is not nearly as bad as one might believe.
In this first report I'll look at the current ice extent and temperatures in Greenland and put these into context. I shall also explore some longer term figures. I shall begin with a few geographical, geological and ice sheet facts. This introductory post is necessarily a long one but my future Greenland posts and updates can refer back to this one as a reference point and can be much shorter!
Greenland Geography:
In this part I am pulling together some of the fascinating facts about Greenland's geography and geology and I draw heavily on data, maps, charts and photographs from Wikipedia. Greenland has an area of 836,330 square miles. To put this into context, the US is about 5 times bigger than Greenland but Greenland is 9 times larger that the whole of the UK.
The island has 27,554 miles of coastline. It stretches for 1,656 miles from north to south between its longest points and 750 miles from east to west at its widest points. Permanent ice still covers most of the landmass at the time of the summer minimum extent. The ice sheet has an area of about 660,000 square miles, a length of 1,500 miles and a width of 680 miles. The average ice sheet thickness is 6,600 ft to 9,800 ft. Much more on this, seasonal variations and longer term trends below.
The country looks much larger than it actually is on most global maps due to flattening out the earth's surface. The map above moves Greenland alongside Africa for a true comparison.
Greenland is very mountainous. If we removed the ice, the island would like it does in the map above. The highest point is Gunnbjorn Fjeld at 12,119 ft and this is the highest peak inside the whole of the Arctic circle - it's located in the east at 68.6N and 29.5W. There are high plateau regions in much of the south and the east and also in parts of the west and, to a lesser extent, in the north. Much of the eastern plateau is well over 2,000 m (6,500 ft). A few of the models (such as JMA) do not adjust mean pressure to sea level equivalents and as pressure is much higher over the elevated plateau this "can" give a very false impression with MSLP sometimes overstated by well over 25mb!
This photograph from the eastern coast shows how the high mountains and the plateau extend right up to the sea for long distances.
Parts of the centre of Greenland, particularly further north are close to or below sea level as can be seen in the "iceless" map above. Surface lakes have been discovered as well as unfrozen water under deep layers of ice. The Greenland ice sheet is actually very mobile. There is some very dense ice in the thickest parts of the ice sheet. Snowfall accumulations in the centre is steadily compressed into ice that flows towards the outer margins just as in Antarctica or with other larger snow fields and glaciers. Very close to the edges, the ice melts in the summer half of the year and also breaks off into icebergs. Snow deposited on the central parts of the ice sheet is gradually compressed into ice. To give an idea of this compression, new snow falling onto the ice sheet has a density of around 60 kilograms per cubic metre while water has a density of 1,000 kilograms per cubic metre. In the central part of the ice sheet the temperature never rises above freezing so the snow never melts (not even with Arctic amplification and warming). Instead, it becomes buried under new layers of snow, with the weight of the new snow increasingly compressing the layers below and steadily becoming denser. Once the density of the snow reaches 830 kilograms per cubic metre, which is around 80 metres deep, all the air passages between the crystals are sealed off so the only air that exists is in trapped bubbles. As the depth increases the density of the ice increases further and at 917 kilograms per cubic metre air bubbles are compressed. At this stage the ice has become glacial ice and it cannot be compressed anymore.
Scientists have been conducting much research into the Greenland ice sheet. Core samples and sophisticated techniques are helping them put together accurate temperature records going back over 130,000 years! We can look into all this fascinating and very important research on this thread. Now I'll move on to the current conditions:
Current Greenland Ice Extent, Summer Melting and Temperatures:
In this section I shall rely heavily on the latest NSIDC data.
This time of year the ice sheet is normally expanding with little or no melt. The white area is where there is no melt and red areas (none now) where there is melting in progress. The grey areas nearer the coast are beyond the main (thicker) ice sheet but are not ice free and in fact they are all snow covered right now. NSIDC explain: "The satellite sensor’s resolution is not fine enough to distinguish ice from land when a pixel overlaps the coast."
This map shows the cumulative melts days for this year to date. The white areas are zero. Around the margins the reds and pinks tell us that there has been some net melting on 60 to 80 days this year. There are one or two isolated tiny brown areas with around 100 melt days.
This chart puts 2018 into context with 2018 (red) compared to the 1981-2010 30 year mean (blue), the last 25 years average (1994-2018) in dark grey and the last 10 years (2009 to 2018) in light grey. The melt season has seen large fluctuations during the summer but was well above average in late July. The melt season, however, came to an abrupt and early finish in mid-August. Here's the reason:
While the Arctic Ocean and almost all the Eurasian Arctic have seen some exceptionally high surface temperatures with very strong +ve anomalies, the Canadian Arctic and almost all of Greenland have seen much lower surface temperatures with strong -ve anomalies. The Greenland average anomaly for this month to date is running at -1.65c but some central and western parts have -ve anomalies exceeding -5c. and widely below -3c. The September average anomaly for all of Greenland was -0.11c. These values are in such stark contrast to those elsewhere in the Arctic region, particularly around the North Pole. These -ve anomalies represent temperatures well below freezing:
Widely below -20c and much of the central eastern plateau is below -40c.
I have produced this interactive chart. It is is available for the entire satellite imagery series from 1979 to date on this link:
https://nsidc.org/greenland-today/greenland-surface-melt-extent-interactive-chart/
I included 2018 (blue line), 2017 (green line), 2012 (yellow line) and 1980 (black line) and compare all these to the 30 year mean, 25 year spread and 10 year spread. It's a somewhat busy chart but I wanted to show the most recent years, the record high melt year of 2012 and the lowest melt year of 1980 for the whole 1979 to 2018 period compared to the longer term averages. Interestingly 2018 had a late start as well as an early finish - so a very short melt season but with some periods of strong melting in mid-summer. 2017 had a longer melt season but with much lower melt rates for much of the time. 2012 completely dwarfs the other years with some exceptional melt rates. The early end to the 2018 melt season is unusual and actually ahead (below) the 30 year mean and well ahead of the decadal average. This is very much due to circulation patterns. It can hardly be down to low solar activity when much of the Arctic region is so warm right now.
This chart shows the model results for the Greenland Ice Sheet snowfall and melt runoff since 1960. The model (MAR 3.9) was run using input from National Centers for Environmental Prediction (NCEP) weather reanalysis data. The surface mass balance (SMB) refers to the net difference between snowfall input and meltwater runoff, or evaporation, loss. The bars show the relative difference from the 1981 to 2010 reference period of observations and modeling.
Not only did 2018 have a short melt season (the yellow bar) which overall was actually below the 58 year mean (the 0 axis), due to its brevity but it has seen the second highest snowfall year to date (the red bar) for the entire period and with 2 more full months to go, it's likely to smash the 1972 record - so a truly exceptional year and some very good news for a change but there is a slight "possible" downside (see my quote from the NSIDC report below). The surface mass balance (blue bar) has seen a lot of negative years since 2006 mostly due to the very high melt rates. 2018 to date has the fourth equal best SMB since 1960, the highest since 1996 and may well end up in second place behind 1972 (no more melting and further snowfall still to come).
This from the most recent NSIDC report on Greenland:
...." exceptional winter snow accumulation and heavy, summer snowfall, drove the net snow input mass to 130 billion tons above the 1981 to 2010 average. This was followed by a near-average melt and runoff period, resulting in a large net mass gain for the ice sheet in 2018 of 150 billion tons. This is the largest net gain from snowfall since 1996, and the highest snowfall since 1972. However, several major glaciers now flow significantly faster than in these earlier years. The net change in mass of the ice sheet overall, including this higher discharge of ice directly into the ocean, is not clear at this point but may be a smaller loss or even a small gain. This is similar to our assessment for 2017, and in sharp contrast to the conditions for the preceding decade. Persistent winds from the northeast triggered high snowfall for 2017 to 2018 along the eastern Greenland coast. These winds blew across open ocean areas allowing the atmosphere to entrain moisture and deposit it as heavy snowfall on the ice sheet....."
The top graph shows the 2018 reflectivity trend for the entire Greenland Ice Sheet through September 15, and four reference years: 2000, 2010, 2012, and 2017. The grey band represents the 5-to-95 percent range for the 2000 to 2009 reference period. The maps below show average monthly albedo, or solar reflectivity, for July 2018, on the left, and August 2018, on the right.
In Antarctica the vast white ice sheet there reflects over 85% of the sun's rays back into space during their summer half of the year and this is known as the albedo effect (I described this process on this thread in a post further up this page). This protects the ice from melting and preserves it. The Greenland ice sheet also has a strong but lesser albedo effect. The top chart compares 2018 (in purple) to recent years. Compared to the 2000-09 average (the grey spread) it's not surprising to see 2018 near the top. All that summer snowfall and increased white surfaces produced a far higher albedo than in many recent years. 2012 saw the lowest values. This from the NSIDC report:
...."High winter and spring snowfall, and a moderate initial pace of melting, resulted in a more reflective (higher albedo) surface for the ice sheet than in past summers. Since bright, fresh snow blanketed areas that were once darker, such as dirty snow or bare ice, July’s average albedo for the ice sheet was 5 to 9 percent above the 2000 to 2009 reference period. Wet snow also has a darker surface, or lower albedo. Increased surface melting, above-average temperatures, and the three spikes in melting, August’s albedo decreased to more average values. However, the albedo along the western coast remained above average....."
Since August we have seen the early end to the melt season, those below average surface temps (well below this month) and continued above average snowfall. It's highly likely that the albedo has been very strong during the last few weeks.
This chart shows the thickness of the Greenland ice sheet. As earlier, the satellite sensory equipment does not pick up very well the areas beyond the continuous thick ice sheet. Those coastal regions are currently ice and/or snow covered. So, although Greenland extends south of the Arctic Circle towards the Atlantic Ocean and is exposed to the jet stream and the Gulf Stream and takes a battering from passing depressions and Atlantic storms for long periods every winter, it's generally high elevation helps it to retain much of its ice sheet and produces some huge snowfalls. It has been impacted by global warming and climate change but, so far at least, not nearly to the same extent as the polar regions and the Arctic Ocean. Some of the hyped reports have been very misleading. I intend to do a post on global ice extent quite soon and this will show the importance of the Greenland ice sheet and more especially the Antarctica ice sheet in, at least, slowing down the impacts of overall ice loss through global warming. We also need to examine the rate of decline and thoroughly analyse the reasons, ignoring both extremes of the climate change debate to get at the facts. David

ANTARCTICA UPDATE
I was planning to do this update next week but with the recent interest shown in Antarctica, I've decided to bring it forward. Firstly I should repeat what I said in my introductory post - when I opened this "Arctic" thread" I always intended it to include Antarctica (see page 1 for my first post on that with loads of facts about it and comparisons to the Arctic) as well as Greenland (I'm planning a post on that later this week), global and glacial ice (posting on that in due course). If we really are going to examine global warming impacts on the Arctic and Arctic warming impacts on the N Hem (in particular) and make a fair and balanced assessment on this thread, then we must include global ice conditions. The Arctic gets most of the publicity due to the very rapid decline of permanent and older ice, the exceptionally high +ve SST anomalies up there and the very high 2m surface temps and I updated the current position on all of these last week. it's also surrounded by populated countries and closer to the N Am and European continents where much of the interest is generated. Meanwhile Antarctica gets far less notice, being an isolated continent. It is however, actually even more important than the Arctic and is the biggest contributor to slowing down the rate of global ice loss (more below on this).
In this post I will look at the current ice extent, the SSTs and the land temperatures down there and put this into context. Before I do that, just a word about James' @Singularity post on here this morning. That's a really nice summary of the recent warming trends in the Arctic and describing part of the feedback loop which has caused what a few call runaway or out of control ice loss and is very much what we shall be examining on this thread. I did a very long post on here "Arctic Report (5) - Longer Term Ice Extent - Putting The Current Position Into Context" (on August 18th, halfway down page 1 on this thread) and I went back through the satellite period which started in 1979 and then further back to 1850 with data based mostly on shipping logs and then a glance at the last 1,450 years where recent very sophisticated research into ice core samples and deep ocean floor sediments have given us a surprisingly accurate record of past ice extent. I really want to encourage a lot more contributions into all of this - facts, figures, analyses and paper reviews and an active debate. Very soon, I shall start reviewing some of the most relevant papers that I placed into the Research Portal and I know that Malcolm @Blessed Weather intends to do the same.
Right, on with my post. I shall comment below each chart.
Current Ice Extent:
Compared to the Arctic, Antarctica's winter sea ice extent is usually much closer to the 1981-2010 mean and in some years, including some quite recent ones, it has actually been close to or exceeded long term record highs such as in 2014 and previously in 2012 (see below).
Source: NASA https://neptune.gsfc.nasa.gov/csb/index.php?section=234
These charts show us 3 different decadal mean periods since the full satellite imagery records started in 1979. It includes the two record high years of 2012 and 2014. We can see that 2018 was running slightly below the means at its minimum point in late Feb/early March and still very slightly below the means right through to the maximum extent in their winter.
This chart tells us that 2018 had a blip in mid- September (due to unfavourable circulation patterns for several weeks bringing warmer than average temps at that time). Then the pattern changed and 2018 actually saw a very late maximum in early October, although 2017 saw an extremely late maximum.
Now this chart is not as important compared to the same one for the Arctic. Being a large land mass the winter sea ice that forms around the coast extends out to relatively low latitudes. The vast majority of sea ice melts each summer and there is practically no older sea ice. The sea ice sheet that reforms each fall is therefore not that thick. I will do another post at some stage on the land ice which is so important and plays a key role in global ice extent.
Sea Surface Temperatures - SSTs:
This chart is very simple at this time of the year when we have just seen the annual maximum ice extent. SSTs are mostly below -1.5c right out towards 60S.
The white areas over and around Antarctica are not neutral conditions, they are ice covered. Much of the ice free regions have -ve anomalies as they have for much of the last 3 months.
This global map shows us the actual values. Even out to just beyond 60S SSTs are close to 0c with values ranging from -2c to +6c.
Until mid September -ve anomalies prevailed over much of the southern ocean and often well beyond 60S. They have recovered slightly with neutral to slightly +ve anomalies now prevailing but still with some regions of -ve anomalies. How different all this is to the exceptional high Arctic Ocean SSTs!
2m Surface Temperature Anomalies:
Antarctica has been affected by global warming but in a very different ways to the Arctic. The temps over the main land mass are actually fairly typical with a trend in the last few years to more +ve anomalies in the west and more -ve anomalies in the drier east. Note that this is not always the case but a slight trend and the contrasts are slightly greater than normal right now. Highest +ves are around 3c to 5c above and lowest -ves are around 3c to 4c below. If you look to the text to the left of the chart this gives some more precise figures. The western landmass anomaly is on average +0.8c while the east is -1.2c (k = kelvin = celius and I'm not sure why they use the kelvin scale). If we include the sea + the land the 60S-90S has a -ve anomaly of -2.4c and going out even further to 66S-90S it is still a -ve of 1.5c. So Antarctica itself, plus its surrounding sea ice and much of the southern ocean as a whole is substantially colder than normal. There is currently some dense cold air over the ice sheet to the north-north west with -ve anomalies as much as -12c there.
Sea Level Pressure:
I do not normally include MSLP charts in my Antarctica reports by I wanted to attempt to answer @jules216's question in the post 2 above this one. He asks:
"My question re Antarctica arose from this GLOSEA 5 seasonal anomaly and the deep blue colors that engulf Antarctica and I wanted to know why is there such a strong anomaly" and I copy the ensemble chart below:
This chart is suggesting that the UK Met Office GLOSEA 5 model is predicting that MSLP will be "slightly" below average during the Antarctica summer. I'm not sure how accurate their forecasts are for that remote region. It's a long range forecast and is subject to change. Slightly lower than average pressure there would produce slightly stronger winds, slightly greater moisture and greater snowfall on the main landmass, perhaps being carried further into the interior than usual. Let's have a quick look at the current pressure charts.
The default pattern is higher pressure on the land mass, particularly over the inland high ice sheets and towards the interior where polar easterlies predominate all the year around. Then low pressure dominating from 60S to 40S ("The Roaring Forties" are the anomalous strong westerlies at 50S to 40S).
So Jules, the answer is that this is not a particularly strong anomaly - just slightly lower pressure than usual predicted to predominate during the Antarctic summer. I hope that this answers your question.
So overall, Antarctica is currently seeing below average SSTs and land temperatures with west/east +ve/-ve anomalies and not far below normal sea ice extent. If these lower temps persist, then the melt season may be rather slower than normal - no bad thing. David

This is a brand new thread for everything to do with the Arctic as well as Antarctica. I hope that many forum members will contribute on here. I have been a keen weather enthusiast for well over 50 years and have developed widespread interests in many meteorological topics. I have always been particularly fascinated by the Arctic and how it interacts with global climate patterns. We have seen a worrying decline in Arctic sea ice extent during the last 30 years and the Arctic has become the centre of the global warming and climate change debate. Whilst this is undoubtedly highly influenced by human activities, there are also some longer term natural changes in play too. I always like to examine the facts and not be overly influenced by exaggerated reports at either end of the debate which has become highly political.

Arctic and Antarctica news and events - special features and reports with comments and analysis (eg: the recent clouds of smoke covering the Arctic from vast Siberian forest fires)

I will add to this list as this thread evolves. In general I would like this thread to appeal to as wide an audience as possible. I'm a great believer in keeping things simple and explaining topics in plain English. I regularly post on the "Teleconnections" thread and some of the more complex subjects such as how does the Arctic ice loss teleconnecton interact with other teleconnections may be more suitable for that thread (or perhaps both threads). There are already some excellent papers and video presentations relating to the Arctic in the "Teleconnections Research Portal" and we will be adding a lot more as winter approaches. Some of these papers may be reviewed on this thread especially when they relate to a particular post.

This list will gradually evolve in line with the thread (so work in progress). If you have a link that you feel is relevant, please draw this to my attentions by "replying to topic" or with a "personal message".

Here's a direct link to the Teleconnections Research Portal - we have placed many Arctic related papers and presentations in there with many more being added during the coming months.

I show an Arctic map (below) to identify the locations of all the seas that make up the Arctic Ocean so that we can comment more meaningfully on the local variations in our posts on this thread.

Antarctica Map:

I will kick things off with a series of short posts to give a flavour of what might follow. I'll do one on the current Arctic sea ice extent later today and two more tomorrow on Arctic sea surface temperatures and Northern Hemisphere snow cover. If I have time, I will do another one on Arctic air temperatures and also show that report on the Arctic ash cloud spreading from those Siberian forest fires. When I return from a business trip, I'll add several more posts later next week.

I would really like to see other forum members getting involved on here with posts and comments and I hope that we can get some debates going too. David

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I always keep an eye on the latest information produced by the excellent National Snow and Ice Data Center (NSIDC) website: (click on this title for a direct link) National Snow and Ice Data Center (NSIDC). Some of this is s updated daily and shows the current ice extent and related data. They also produce a monthly report and the most recent of these was just published on 2nd August, 2018 and is available on the same link as above. This includes a review of the changes during July. Let's have a closer look at some of the recent charts and I'll comment on these below each chart:

The chart (above) shows the current overall sea ice extent over the whole Arctic region. The orange line is the median and shows the edge of the ice cover averaged over the 30 year period from 1981 to 2010. The ice extent reached it's winter maximum on 17th March, 2018 and has declined steadily since during the Spring/Summer melt season. The average sea ice extent for July 2018 was 8.22 million square kilometers or 3.20 million square miles. I'll compared 2018 to earlier years in a minute.

The sea ice concentration map gives us a good clue of where imminent melting is mostly likely. The white shades represent continuous ice cover and the middle to lighter blue shades are areas with more than 50% ice cover but with areas of open water in between. The middle to darker shades of blue are areas with below 50% ice cover. The very dark blue shades are areas with less than 15% ice cover and are mostly open water. These areas likely to be almost completely ice free within a few weeks and thru September which usually sees the minimum ice extent prior to the start of the re-freeze in the fall. The rate of melting is related to prevailing wind patterns (with stronger winds from warmer sources leading to a faster melt), sea surface temperatures (which I'll cover in my next post tomorrow) and cloud amounts (the albedo effect of white ice reflecting sunshine, is stronger under clear skies and can reduce the melt rate). These and other local influences can lead to wide variations from year to year and in different parts of the Arctic and we can examine many of these in later posts.

This chart shows the anomalies in ice concentration for July 2018 compared to the 30 year mean July values (1981 to 2010). The blue shades are negative anomalies and the red are positive anomalies. So the large area of dark blues show that the ice concentration is run at 50% or more below its mean for this time of the year. The total anomaly of 1.1 million square km is shown at the bottom of the chart. The light grey circle around the North Pole is not imaged by the satellite. There are only minor areas with positive anomalies with the largest in the east Hudson Bay. Ice usually melts there about 1 month later than on the edges of the main sea ice sheet due to it being surrounded by land. The melt this Spring was particularly late due to the prolonged colder than average conditions up there caused, at least in part, by the February sudden stratospheric warming (much more on that SSW event on the teleconnections thread).

This graph "can" be misleading as it looks like 2018 (the blue line) is second worst only to 2012 but 2012 (the dotted line) is shown separately as it was the record low year by the end of the melt season in mid-September. While 2018 is running way below the 1981 to 2010 30 year mean it "was", until last month, running quite close to the decadal mean and around 5th worst. The next chart puts this into context.

This chart compares 2018 to the last 4 years as well as the record low year of 2012. During April and May, 2018 was running close to lowest on record but the melt rate slowed during June and early July, mostly due to well below average air temperatures at that time. During the second half of July 2018 melting accelerated again and 2018 is now roughly equal second worse with both 2017 and 2016. Let's look at the early part of 2018.

In January and February, 2018 was running at the lowest levels of ice build up on record, sometimes trading places with 2017. A late recovery during March saw 2018 just avoid the all time low with ice extent marginally higher than in 2016 and 2017. The last 3 years ran neck and neck during April as the Spring melt began (see previous for May onwards).

This chart shows the ice extent anomalies for each July from 1979 to 2018 compared to the 30 year mean (1981 to 2010). Allowing for year to year variations the trend is substantially downwards. (I'll do another post in a few weeks time looking at much longer term and historical ice levels).

This chart was last updated in March 2018 (I could not find a more current one) but it still serves its purpose. It shows the age of the ice. While fresh ice forms or reforms during every winter half of the year, most or all of this "new" ice melts during the summer half of the year. The more permanent ice can be many years old. The chart shows the ice "age" for 1, 2, 3, 4 and 5+ years. It compares the 2018 ice to that of 1984 for the same period (week 9 or early March). The red shows the 5 year old or greater ice extent. In chart (a) in 1984 there was a large expanse of older ice but there is practically no older ice now - just a tiny amount hugging the north Greenland northern Canadian islands coasts. The bottom left chart (c) shows how this trend has continued for the whole 34 year period. Most of the 5+ and the 4+ year ice has disappeared and the less than 1 year old ice has increased at the expense of the old ice. The volume of 2 and 3 year old ice has remained pretty constant but if this trend continues, once there is practically no 5+ year old ice remaining then ice with ages of successively shorter years will melt faster. The loss of this more permanent ice is even more serious than the overall ice loss as new ice is much thinner and melts much more quickly.

The current NSIDC report has a special feature on the Beaufort Sea (please refer to the Arctic map in my introductory post to this thread). This part of the Arctic on the Canadian side used to have some of the oldest remaining ice.

I quote their comments about this:

"Ice concentration over much of the Beaufort Sea has rapidly declined over the past couple of weeks. July 27 imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the NASA Terra satellite showed a large off-shore region with broken-up ice and small ice floes vulnerable to rapid melt by the surrounding ocean (Figure 4a). Sea ice concentration data provided by the University of Bremen from the higher resolution Japan Aerospace Exploration Agency (JAXA) Advance Microwave Scanning Radiometer 2 (AMSR2) showed an expanding open water area within the ice pack between mid-July and August 1 (Figure 4b). By August 1, substantial open water was found throughout the Beaufort. On the other hand, near the coast to the east of Utqiaġvik (formerly Barrow), more compact and likely thicker ice remains, which is less likely to rapidly melt away. How much of the Beaufort ice cover survives the summer and how much more melts away will depend considerably on the weather conditions over the next four to six weeks."

Right that's enough for now. I'll do an Arctic sea surface temperature update tomorrow and, if I have time, another post on Northern Hemisphere snow cover.

David

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I have spent many long Winter evenings going through the vast amounts of data on the excellent NOAA site, the sub-sites and their archive records. For this report, I have accessed part of their "Environmental Modelling Center and Analysis Branch" on this link:﻿http://polar.ncep.noaa.gov/sst/ophi/ This takes you to their SSTs page. These are divided into current analysis and anomaly charts. The top chart on their site shows current global SSTs. You just click on any part of that chart to find the regional charts. The second chart shows current global SST anomalies with the same regional chart access. I show the current Arctic charts below.

Arctic SSTs for August 7th, 2018:

The critical level of SSTs for ice formation is at or below the -1.5c threshold (the bluish/purple colour on the map). In calm conditions, sea water will usually start to freeze when it is below -2c but that is for normal salinity. There is slightly lower salt content in the Arctic (mainly due to snow and ice melt) and the threshold is nearer to -1.5c. The sub -1.5c area is punctuated with a few spots with higher SSTs, even very close to the North Pole. There are some areas with SSTs well above freezing between Svalbarrd (the island group about 500 miles east of the north-eastern coast of Greenland) and off the north-west Scandinavian coast as well as around Iceland. To put this into context we need to examine the anomalies char.

Arctic SST Anomalies for August 7th, 2018:

The SST anomaly chart shows that there is a wide area of open water in the Arctic with well above average surface temperatures (the white sea areas are still at least partly ice covered and not open water (see the ice extent charts in my previous post). That area around and south of Svalbard has current anomalies widely over 4c above average (the dark brown colours) and over 8c above in several places (the olive green colours). Even with a warming Arctic and extensively above average SSTs over many parts of the globe, these are truly exceptional anomalies. These are partly a long term legacy of the 2015-16 winter when the Atlantic jet stream powered almost continuously well into the Arctic for much of the first half of that Winter during the peak of the "super El Nino" episode. This shifted much warmer than average currents right up to the edge of the main ice sheet. This strong anomaly has persisted for 3 years and shows little sign of reversing. Unless the SSTs reduce substantially, the anomalies will be carried through this summer and into a fourth winter. This summer the jet stream has generally taken a more northerly track than usual. While this allowed those widespread heatwave conditions to persist over large parts of the middle latitudes, it has also pushed yet more warmer waters into the Arctic Ocean. There is a far greater influence on the North Atlantic side of the Arctic which is much more open and exposed compared to the more land locked North Pacific side. These warmer waters are occurring despite much of the Arctic having relatively cooler than average air temperatures (which I'll cover in another post later today). There is a small area of the North Atlantic, mostly southwest of Iceland and off the southern tip of Greenland with a negative anomaly (the green shades).

David

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Thank you for starting this dedicated Thread David. What's happening in the Arctic has enormous implications for global weather and climate going forward, with plenty of evidence that we are already seeing the impact of ice loss. I intend to be a regular contributor to this thread.

A brief start by showing a couple of charts produced by a guy who specializes in this field - Zach Labe from the Department of Earth System Science at the University of California, Irvine. Well worth following on Twitter. Here's his personal page. http://sites.uci.edu/zlabe/

Anomalous sea ice conditions continue on the Atlantic side of the Arctic. Sea ice extent in this region is a satellite-era record low for the date (previously held by 2016). Each thin line shows one year from 1979 [purple] to 2017 [white]:

Nearly the entire Arctic Ocean has sea ice thinner than the climatological average for the month of July. This is especially found north of Greenland in this data set:

Finally, an interesting website called "Polar Science Center" with all sorts of fascinating info: http://psc.apl.uw.edu/

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Thank you for starting this dedicated Thread David. What's happening in the Arctic has enormous implications for global weather and climate going forward, with plenty of evidence that we are already seeing the impact of ice loss. I intend to be a regular contributor to this thread.

A brief start by showing a couple of charts produced by a guy who specializes in this field - Zach Labe from the Department of Earth System Science at the University of California, Irvine. Well worth following on Twitter. Here's his personal page. http://sites.uci.edu/zlabe/

Anomalous sea ice conditions continue on the Atlantic side of the Arctic. Sea ice extent in this region is a satellite-era record low for the date (previously held by 2016). Each thin line shows one year from 1979 [purple] to 2017 [white]:

Nearly the entire Arctic Ocean has sea ice thinner than the climatological average for the month of July. This is especially found north of Greenland in this data set:

Finally, an interesting website called "Polar Science Center" with all sorts of fascinating info: http://psc.apl.uw.edu/

SNIPPED

Thank you for your kind comments Malcolm and welcome to this exciting new thread. I'll look forward to all your future contributions and that's a fascinating first post you've done. Yes, the Atlantic side of the Arctic as well as the Beaufort Sea on the Canadian side (that I alluded to) are losing ice even more rapidly this year and older is ice is thinning at a really worrying rate. We can closely monitor the remainder of the summer melt season on this thread. Let's hope for an early re-freeze in the fall but I'm not at all optimistic about that.

I'll add those links that you've provided to the "useful links" list in my introductory post. I've come across Zach Labe and he's been building up his excellent website during the last year or so. I've posted some of his charts on a UK weather forum before in one of my Arctic reports on there and his work will feature strongly on this thread. He's written several fascinating recent papers and there are links to these and others on his site, mostly connected with the ice loss. We will need to add many of these papers and presentations into the Teleconnections Research Portal (for readers, just click on the title for a direct link) and then we can review a good number of them on here in the coming weeks and months. David

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In this post I'll focus on the current Arctic air temperatures and anomalies. Let's start off with the current GEFS T+0 charts:

These are 0200 GMT 2m surface temperatures, so closer to the daily minimum values. Almost all the Arctic is above 0c and only the Greenland plateau and ice sheet are substantially below freezing point (I'll show mean temperature in a minute).

The Climate Reanalyzer site base most of their research analysis and charts on GFS output but as I'm looking for current (or historic) data and not predictions, the choice of model is not important here - just a clear representation. Here's a link to their site: https://climatereanalyzer.org/wx/DailySummary/#t2Their range of output is listed on the left of each chart or map and the one shown is highlighted in red. The one above shows the "average" current 2m surface temperatures with a focus on North America and the Arctic - ideal for this forum!

Almost all of the Arctic is currently seeing above average 2m surface temperatures with the regional average of +1c which is considerably higher than the global anomaly and the northern hemisphere anomaly. Parts of Greenland and the Siberian side of the Arctic have much higher anomalies of up to a mammouth 10c above average! Only parts of Alaska and Iceland (which is having one of its coolest summers on record) have negative anomalies. Overall. Arctic surface temperatures this summer have not been quite as high as in recent summers but they are still well above the 30 year means (more on this later on).

Unsurprisingly, the distribution of the upper (850) temperatures are fairly similar to the near surface temperatures.

The 850 positive anomalies are highest over the North Pole and Greenland and the negative anomalies are lowest over Alaska, Siberia and also over north-west Russia, north-east Scandinavia and Iceland.

In my UK forum Arctic reports, I focused on a particular site to look at temperatures, means and anomalies in more detail and to monitor them in each update (at least monthly and more frequently in mid winter). I shall continue with this feature on this thread. I look at readings from Svalbard, the most northerly island group on the Atlantic side of the Arctic (more details in a minute). When you see what I show below, perhaps several other members might like to provide a monitor for some other Arctic weather stations. For US members, we could do with at least one Alaskan regular reading, perhaps one from north-east Canada, northern Greenland (which will feature a lot on this thread) and northern Siberia and/or, north-west Russia.

So, as this is my first post of this type on this thread, let me introduce Svalbard to you and then I can refer back to this post when I do future updates:

Svalbard is roughly midway between the northern Norway coast and the North Pole and the islands are only about 600 miles from the pole. The group of islands range from 74N to 81N and from 10E to 35E. They were discovered by "Scandinavians" in the 12th century and Norse men gave the islands the name of Svalbard which means "cold shores". The Dutch mapped the group in the 17th and 18th centuries and named them Spitsburgen and this remains the name of the largest island but in 1925 when Norway took administrative ownership (previously unclaimed by any country) they officially named the group as Svalbard. The capital is Longyearbyen.

At the end of a typical recent winter, the main Arctic ice pack just about reaches north-east Svalbard but it used to completely engulf them until the 1980s (I'll do a separate post on historic ice extent before long). The West Spitsburgen current runs up between Greenland and Svalbard. The is the northernmost extension of the North Atlantic Current (or Drift) and the Gulf Stream. This modifies winter temperatures which are higher compared to those at the same latitudes in Canada and Russia. This discrepancy was around 2c but has been greater in recent years (see below). Over 60% of the main islands are covered in permanent glacial ice as the islands are quite mountainous as can be seen in the topographical map above. There is quite a temperature contrast across the islands and I look at readings from and forecasts for three different stations. I provide all three links below but I'll just focus on the Longyearbyen station:

Please note that the links above will update automatically at frequent intervals throughout the day. They are the Norway met office’s predictions. We need to be aware that these are only a forecast that is subject to change and I am told that the Arctic surface temperature forecasts are not completely reliable even at quite short range.

The red bars show the daily maximum and minimum temperatures and the red line represents the daily average temperature. The black line represents the 30 year mean (1980 to 2010) or average mid point between the minimum and maximum temperatures. Note that the average temperatures were continuously above the mean and, for more than half the period, even the minimum temperatures were above the 30 year mean! The blue bars show precipitation.

Svalbard Airport, Longyearbyen - Temperatures for the Last 13 months:

This chart shows us similar information but for 13 months. Instead of bars the daily temperatures are shown on lines. The blue colour is when the temperature falls below 0c. Again note that even the minimum temperatures rarely dropped below the 30 year mean.

This last table shows the average temperature for each month, then the normal temperature (monthly means) and the highest and lowest temperatures for each month and the date that it occurred on. This has just been updated with the July 2018 figures when the monthly average temperatures were 1.3c above the 30 year mean. Note that this excess is actually the lowest monthly amount for any of the last 12 months but July 2017 was slightly less warm and saw a 1c excess. The largest excesses occur in mid winter with over 10c above average in February 2018. Svalbard has been seeing average temperatures often running at 3c to 8c above their long term average throughout most of the last 5 years. This is reflective of the warming Arctic and the near record low sea ice cover.

Overall, the temperature profile for the whole of the Arctic is extremely worrying. The second lowest ice-build up on record last winter, getting close to the lowest levels on record during the 2018 melt season, older permanent ice thinning and melting and record high sea surface temperatures with the anomalies going even higher in some parts. We need to examine longer term trends and discuss all the causes.

I'll be back a little later with a short post on the Arctic ash plume caused by Siberian forest fires. David

The US members on this forum will be only too well aware of the major forest fires in California and Colorado during this summer. Many of us that follow global news will be aware of the devastating fires last month in Greece. In the last week or so Spain and particularly Portugal have seen close to record high temperatures with some major fires there. Sweden has seen drought conditions and heat which sparked off the biggest fires ever seen there. Even here in the UK, we had major fires on our north western hills with heathland covered in drying out peat bogs (peat is highly combustible and is actually used as a fuel). These fires have been almost impossible to put out as the peat smoulders underground..

Now, how many of us have read about the huge forest fires in Siberia and what widespread impacts they have had?

Well a few of you may have seen the NASA report on July 11th:

The smoke plumes from northern Siberia actually reached as far as Canada, the Great Lakes and New England in northern USA! It's that milky blue/grey layer below all the clouds. A few Canadians reported a burning smell.

Much closer to the source region and en route to Canada was the Arctic.

These images from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor show the Arctic Ocean and surrounding land from July 3 to 6, 2018. Blue arrows indicate smoke that had drifted from fires in Siberia.

On July 17th NSIDC (the National Snow & Ice Data Center) made these comments:

"Fires in the western United States have been much in the news lately. Less noted are significant fires in Siberia. Over several days at the beginning of July, smoke from these fires was brought into the Arctic Ocean by winds associated with the pattern of low pressure in the region. The smoke streamed over the East Siberian, Chukchi, and Beaufort Seas and eventually across Alaska into northern Canada. The smoke has two potential effects on sea ice. First, as it drifts over the ice, the smoke particles scatter solar radiation and reduce how much is received at the surface. This has a cooling effect that will tend to reduce the rate of ice loss. However, smoke particles that settle onto the ice will darken the surface, thus decreasing the reflectivity of the surface, or albedo. This increases the amount of solar energy absorbed by the ice and enhances melt. The atmospheric scattering effect of the smoke is short term and dissipates after the smoke drifts away. The surface albedo effect has a longer-term impact and could serve to enhance melt rates through the summer. The magnitude of the effect will depend on how many smoke particles are deposited on the surface, the albedo of the surface that the particles fall on, and the amount of cloud cover which reduces the incoming sunlight. The biggest effect would be on bright, snow-covered ice. It would be smaller on darker melting ice and melt ponds, and there would be no effect in open water areas."

The Siberian fires started as far back as early May following months of drought conditions and then a series of lightning strikes from dry thunderstorms. Some of them are still burning strongly now. The smoke plumes have travelled over 5,000 miles. Winds have varied but the Arctic is still in danger. As NSIDC say, smoke can blot out the sun and actually lower air temperatures but ash fall out can darken surfaces and reduce the albedo effect - the ability of white /bright snow to reflect sunlight. So let's look at the albedo effect a little more closely.

This excellent charts shows that clear snow and ice reflects about 90% of solar energy straight back into space. Open water, on the other hand, absorbs about 94% of solar energy. This compounds the effect of ice loss. Various tests have demonstrated that darkened snow cover, such as snow covered in ash deposits will reflect less than 50% of solar energy and the darker it is the lower the reflective properties or the albedo effect. So, if we didn't have enough trouble with near record levels of ice loss in the Arctic, the last thing we need are major forest fires and what little ice and snow that remains being darkened by ash fall out. Unfortunately, if climate change is largely to blame, we can expect more drought conditions and heat waves and yet more frequent and extensive forest fires. A nasty vicious circle. We can explore this and a lot more on this thread.

David

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Just a very short post this time. One of the regular features on this thread will be monitoring northern hemisphere snow. The snow build up usually gets going in October and November and in the last couple of winters, substantial Asian snow cover had a very early October start. It will be fascinating watching the build up to the 2018/19 winter and comparing it to previous winters. There are a few excellent sites that produce snow cover charts and maps. I particularly like the NOAA site which is about the most comprehensive one available with many options - here's the link: https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/ That link takes you to the snow cover map home page and you'll see this:

I set the map to the current northern hemisphere view which includes the Arctic. The regional views available are: USA (including Canada), Alaska, Europe/Asia and they have just added Afghanistan and plan to add more soon. You can select any date from 1997 to the current map as well as a date range and then set the animation feature - this is brilliant for monitoring the progress of new snow cover (or the decline). Unfortunately this site does not seem to have a gif option, so we cannot reproduce the animations on this thread (several other sites do allow this option and we can show those too when relevant). Snow cover is getting close to its minimum annual extent during August/September but there can be temporary cover with any early cold incursions in the prone spots. Here's a small selection of maps:

This is at the same time last year. Note that although it is very similar, there was a little residual snow cover over small parts of Asia (ignoring the higher mountain ranges which maintain permanent snow cover). The Asian heat wave in the middle latitudes this summer has melted snow up to quite high levels.

When there is more to report during the fall, I shall add more commentary below each chart. David

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While this is essentially an "Arctic" thread, I feel that we should monitor conditions in Antarctica too as well as Greenland and global glaciers (if no one else has in the meantime, I may well do a report on the latter two within a week or two). We shall be examining global impacts and climate change and there are significant geographical differences between the two polar regions and they contribute to the global climate in rather different ways. In this report I shall look at the current conditions in Antarctica. Then I'll consider some of the facts and identify some of the contrasts between the two regions. I shall also review a relevant learning guide fact sheet that I placed into the Research Portal. For a physical map of Antarctica, please refer to the one I placed in my introductory post as a permanent reference point.

Sea Ice Extent:

The excellent National Snow and Ice Data Center (NSIDC) website: (click on this title for a direct link)National Snow and Ice Data Center (NSIDC) which I referred to in my "Arctic Report (1)" post also provides regular updates on Antarctica.﻿

Sea ice surrounding Antarctica usually reaches its maximum annual extent between late August and mid September depending on weather types and patterns - so we are not far off this year's maximum now. Overall sea ice build up has been quite close to the long term mean. Much of western Antarctica is slightly above average while much of eastern Antarctica is slightly below average with a few larger positive and negative variations.

Here's the NSIDC most recent monthly Antarctica report:

Antarctic sea ice update

Sea ice in the Southern Hemisphere grew at a slightly faster-than-average pace from June through mid-July, but then slowed through the second half of July. At mid-July, ice extent was near average in all sectors except the region north of Dronning Maud Land. In the last two weeks of July, an area of below-average ice extent developed north of Wilkes Land in response to warm winds from the northeast, reducing the overall ice growth and bringing the Southern Hemisphere ice extent down relative to the 1981 to 2010 average (below the range of 90 percent of the past observational years). Above average temperatures at the 925 hPa level (about 2,500 feet above sea level) of 4 to 5 degrees Celsius (7 to 9 degrees Fahrenheit) occurred over the northern West Antarctic coast and the southern Peninsula, where the Peninsula high pressure ridge brought winds from the north. Temperatures 3 to 6 degrees Celsius (5 to 11 degrees Fahrenheit) above average also occurred along the Wilkes Land coast.

Sea ice concentration distribution is quite similar to the overall extent and mostly at 70% to 100% (ie: little or no open water) except close to the edges). The variations of sea ice concentration are far greater in the Arctic (comparing times of maximum ice build up).

Unlike the Arctic which retains sea ice throughout the year, albeit at worryingly reduced rates, Antarctica loses the majority of its sea ice each summer (more on that later). The chart above was around the time of the summer minimum which usually occurs between late February and early March. Interestingly, the greatest anomalies (with the lowest ice remaining) were adjacent to western Antarctica and yet this area has seen the strongest re-freeze this winter!

NSIDC made the following comments about the minimum Antarctic ice extent in their March report:

The Antarctic minimum

As noted in our previous post, in the Southern Hemisphere, sea ice reached its minimum extent for the year on February 20 and 21, at 2.18 million square kilometers (842,000 square miles). This year’s minimum extent was the second lowest in the satellite record, 70,000 square kilometers (27,00 square miles) above the record low set on March 3, 2017. The Antarctic minimum extent is 670,000 square kilometers (259,000 square miles) below the 1981 to 2010 average minimum of 2.85 million square kilometers (1.10 million square miles).

The February 20 and 21 timing of the minimum (the same extent was recorded on both dates) was just slightly earlier than the 1981 to 2010 median date of February 24 for the minimum. Over the satellite record, the Antarctic minimum has occurred as early as February 15 and as late as March 6.

Compared to the Arctic, air temperatures over the sea ice regions of Antarctica over the past season (austral summer) have been closer to their climatological average, hovering within 2 degrees Celsius (4 degrees Fahrenheit) of the 1981 to 2010 average. Relatively rapid and early growth of ice along the eastern Weddell Sea ice edge led the beginning of the autumn sea ice expansion

Sea ice build up has been running at a slightly higher level compared to 2017 and is only slightly below the 1981 to 2010 mean. Year to year variations are much smaller than in the Arctic and the winter re-freezes have not been declining. In another post (and perhaps some other members will comment on it too), we need to examine the land ice, the ice shelves, snow cover and snow and ice depth and the weather patterns around Antarctica. There are conflicting studies on the overall ice extent across all of Antarctica - not least because it's so thick in places (over 3 km) and difficult to measure. Climate change and warming seas are producing much greater snowfall, especially so in the previously much drier east. This has in turn accelerated the glacial flows with snow and ice on the high plateaus (which cover much of the Antarctica landmass) spreading out coastwards and this is why more ice shelves have been breaking off in recent years. I follow the Antarctic Survey work and I'll do a separate post in due course on their valuable and fascinating research and findings. This thread is the place for all of us to get stuck into this!

This charts shows how little annual (maximum) ice extent anomalies have changed since 1980 - perhaps a shade lower in 2016 and 2017 but above average from 2012 to 2015. No strong downward trend at all compared to the Arctic as I demonstrated in my Arctic Report (1).

Sea Surface Temperatures:

I'll show the excellent NOAA charts that I used in my Arctic Report (2).

At first sight these SST charts show far less detail compared to the SST charts that we're used to viewing elsewhere, including those for the Arctic. Remember that we are at the height of Antarctica's winter. The white represents land and sea ice. The mauve is open sea (or where ice concentration is below 15%) and where SSTs are below -1.5c. In my Arctic report (2) SSTs post I said this: "The critical level of SSTs for ice formation is at or below the -1.5c threshold (the bluish/purple colour on the map). In calm conditions, sea water will usually start to freeze when it is below -2c but that is for normal salinity. There is slightly lower salt content in the Arctic (mainly due to snow and ice melt) and the threshold is nearer to -1.5c". The seas surrounding Antarctica are completely exposed and the circulation is much stronger than around the more landlocked Arctic and winds generally blow harder (eg: "The Roaring Forties"). There is sea ice melt, land ice (ice shelves) breaking off and ice/snow transported to the coast from well inland which reduces the salinity slightly but this is counteracted by the circulation and winds. The net effect is that the freezing level for Antarctic sea ice to form is nearer -2c and at least 0.5c lower than that required for Arctic ice to freeze. There are practically no areas of water with SSTs above 0c except near the extremities.

Conversely, the strong circulation around Antarctica also protects it from other global patterns and Antarctica is less susceptible to the changes from surrounding areas compared to the landlocked Arctic which can be strongly influenced by land extremes, eg: that Siberian smoke plume I posted on or the jet stream pumping in warmer waters from the Atlantic. There are so many fascinating differences for us to get our heads around.

Moving on to the anomaly chart, again in the depth of winter we see that open water and areas with up to 15% sea ice concentration (compare this with the ice concentration chart above) show practically no anomaly. Further out, in stark contrast to the Arctic, the SST anomalies are mostly below or well below average - from -.0.25c to -.2.25c with only minor patches of above average SSTs. It'll be fascinating to monitor how these Antarctica SSTs change during the summer melt season. We also need to look into recent trends and compare the Antarctic Ocean to global SSTs and circulation patterns.

A Few More Facts About Antarctica Compared to the Arctic:

Here's a guide that I placed into the Research Portal a few weeks ago: Quick Facts on Arctic Sea Ice (just click on the title for a direct link to the portal and from there a link to the facts sheet). Firstly, I should point out that it includes facts about Antarctica too! It's yet another NSIDC document/paper and it's an excellent early learner's guide and also covers some facts that many of us may not be aware of. It has been updated earlier this year. It has facts on:

Arctic Sea Ice

Antarctica

Ice Shelves

Ice Bergs

There are many links from there and overall, there is a wealth of information and I'm sure that we'll be making frequent references to this in our posts on here. I want to do a post on ice shelves before too long. Ice bergs are both dangerous and fascinating. That huge Arctic ice berg that dwarfed a small inhabited Canadian Arctic island made the news several months ago but that is small fish compared to the vast ice bergs and ice shelves that are regularly carved out in Antarctica.

I quote this part from the guide:

Is Antarctic sea ice important, too? Is it shrinking?

Scientists monitor both Arctic and Antarctic sea ice, but Arctic sea ice is more significant to understanding global climate because much more Arctic ice remains through the summer months, reflecting sunlight and cooling the planet. Sea ice near the Antarctic Peninsula, south of the tip of South America, has recently experienced a significant decline. The rest of Antarctica has experienced a small increase in Antarctic sea ice. Antarctica and the Arctic are reacting differently to climate change partly because of geographical differences. Antarctica is a continent surrounded by water, while the Arctic is an ocean surrounded by land. Wind and ocean currents around Antarctica isolate the continent from global weather patterns, keeping it cold. In contrast, the Arctic Ocean is intimately linked with the climate systems around it, making it more sensitive to changes in climate.

That is very much in line with my earlier comments but I would slightly take issue with one point that NSIDC make. I feel that the changes in Antarctica are at least as important as those going on in the Arctic - yes they are very different and contribute to global weather circulations and patterns very differently. We might need to learn a lot more about the Arctic and climate change but scientists are still well behind the curve when it comes to understanding the changes and influences from Antarctica. I strongly believe in "balance" and I hope that we can all review and comment on these topics on this thread in a search for the actual facts and causes.

I have many more papers and presentations to place into the Research Portal (some excellent ones are in there already - just go through the index where there are a number of Arctic and an Antarctica heading). Everyone is welcome to review any relevant paper on here. If you find some good ones that are not already in the portal, I'll happily add these - just provide the link and the details (full instructions are set out in the "Interactive Area" of the Research Portal - again just click on the title for a direct link).

Finally, I'm hoping that Zac (@Snowy Hibbo) our Australian friend who set up the teleconnections thread on 33, will provide us with some of his wisdom on here with posts on the southern oceans and Antarctica to provide some balance to all the Arctic posts that most of us are likely to focus on. Zac did a brilliant post on the teleconnections thread on June 2nd. Here's a link to the page (it's about halfway down page 3):

He describes the AAO (Antarctic Oscillation) also known as the SAM (Southern Annular Mode). I was particularly fascinated by the Antarctic Sudden Stratospheric Warming (SSW) event of 2002 - so far the only SSW ever recorded in the southern hemisphere.

David

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Well here's another very interesting chart produced by Zach Labe. A great way of looking at how Arctic air temperatures have been steadily increasing during the satellite era (since 1979). There seems to have been a notable 'flip' as we entered the 2000's. Worrying.

Absolutely Malcolm, that has been the case for most of the last 10 to 20 years and particularly in the last decade - so we're reduced to comparing the recent years to each other as they are all well below the 1981-2010 30 year mean. 2018 was not quite as bad as 2017 and similar to the 4 previous years as at July 31st. I explained this in my Arctic report (1) post last week. I'll just repeat the decadal chart here for comparison:

2012 is also shown a that saw the record lowest ice extent. With 3 to 4 weeks to go until the usual minimum extent, just where will we end up - perhaps the second worst on record?

I am putting together a post on much longer ice extent records going back to the 1920s. I may get this done late tomorrow or over the weekend. Meanwhile, here's a comparison that shows the Jan and Jul ice extent for 2018 and 1980:

I picked out 1981 as that was when the 30 year mean started and it was a slightly below average ice extent year (compared to the 1981 to 2010 mean). So no exaggerations and hype. Even so, what an extraordinary difference. The charts are quite small (I'll do bigger charts in my main post tomorrow) - so here are the ice extent figures:

January 1981 - 14.9 million square kilometers.

January 2018 - 13.1 million square kilometers.

July 1981 - 10.3 million square kilometers.

July 2018 - 8.2 million square kilometers.

As I said, I could have picked out a much colder period like 1969 which had far more ice. (I'll show that tomorrow and pit it into full context). Note that the extent differences are relatively greater in the summer (2.1m sq km less in July 2018 and 1.8m sq km less in January 2018 compared to the 1981 values. In my report (1) I showed a chart with the age of the ice. Most of the ice that re-forms in winter melts more or less completely the following summer. The older has been melting in recent years with hardly any 5+ year old ice remaining. So, although there is new open water in the summer, this re-freezes quickly in the winter but as thin unstable ice. David

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ARCTIC REPORT (5) LONGER TERM ICE EXTENT - PUTTING THE CURRENT POSITION INTO CONTEXT

In this post I will go back a lot further and examine ice extent changes and anomalies over the last 150 years and compare these to current levels. I introduced this comparison in my reply to Malcolm's (@Blessed Weather) twitter post yesterday. In my first Arctic report (the second post down on this thread) I reviewed current ice extent and looked at the excellent NSIDC data. As we are getting very close to the seasonal minimum ice extent (usually between late August and mid September largely depending upon prevailing circulation, wind and weather patterns), I shall start off with the current position:

Arctic sea ice extent for August 16th, 2018 was 5.7 million square kilometers (2.2 million square miles). The orange line shows the 1981 to 2010 average extent for that day

"Approaching Autumn, Pace Slows - After declining rapidly through July, sea ice extent decline slowed during the first two weeks of August. A new record September minimum is highly unlikely. Our 2018 projection for the sea ice minimum extent falls between the fourth and ninth lowest in the 40-year satellite record. Two NSIDC scientists are studying ice and ocean conditions in the western Arctic aboard an icebreaker. As of August 15, Arctic sea ice extent was 5.7 million square kilometers (2.2 million square miles). This is 1.58 million square kilometers (610,000 square miles) below the 1981 to 2010 average, but 868,000 square kilometers (335,000 square miles) above the record low at this time of year recorded in 2012. Ice retreated recently in the Kara, Laptev, and Beaufort Seas. The ice edge was relatively unchanged near Greenland and Svalbard, and in the East Siberian Sea. Much of the Northwest Passage through Canada remains choked with ice. The Northern Sea Route appears open, according to the Multisensor Analyzed Sea Ice Extent (MASIE) analysis, though ice is lingering near the coast in the East Siberian Sea. Scattered ice floes are likely present along the route. A large patch of sea ice, separated from the main pack, persists in the southern Beaufort Sea. Such patterns of ragged patchiness or large polynyas have been a more frequent feature of Arctic summers since 2006. Through the first two weeks of August, ice extent declined at approximately 65,000 square kilometers (25,100 square miles) per day, slightly faster than the 1981 to 2010 average of 57,000 square kilometers (22,000 square miles) per day. Sea level pressure was above average over the central Arctic Ocean, a change from last month, flanked by areas of below-average pressure in the Kara Sea and northern Canada. Temperatures at 925 hPa (about 2,500 feet altitude) were generally 1 to 5 degrees Celsius (2 to 9 degrees Fahrenheit) above average over much of the Arctic Ocean for this period, with the area just north of Greenland reaching 5 to 7 degrees Celsius (9 to 13 degrees Fahrenheit) above average. Below average air temperatures persisted over the Kara Sea, 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit), and the Beaufort Sea, 1 to 5 degrees Celsius (2 to 9 degrees Fahrenheit). Another feature of note is the region of open water along the north coast of Greenland, around Cape Morris Jesup, which is visible on August 13 in Moderate Resolution Imaging Spectroradiometer (MODIS) Terra true color imagery from NASA WorldView. The region normally consists of thick, consolidated ice from a general pattern of on-shore ice motion. Even when winds blow offshore, the strength of the thick ice would hold in place along the coast. However, current ice conditions appear more broken up and likely thinner, and over the past couple of weeks, offshore winds have succeeded in pushing ice off of the coast."

This shows a true color composite image of Cape Morris Jesup off of northern Greenland, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the NASA Terra satellite on August 13, 2018.

Here's a current snapshot of that area off the north coast of Greenland that NSIDC refer to above from the "NASA WorldView" that we can keep monitoring:

So, in terms of the last few years' minimum ice extent, this is marginally better news with the melt not quite as extreme as was predicted right up to last month. For those interested in the different seas and the references made to them, please look at the Arctic Ocean map that I placed in my introductory post to this thread. That open water off the north coast of Greenland is very disturbing and the thinning of the previously thick multi year ice in the Beaufort Sea slightly further northwest (referred to in my first Arctic report) is equally worrying.

This chart compares the 2018 ice extent to the previous 4 years + the record low extent year of 2012. The slowing of the melt rate since late July is quite clear with only 2014 having more ice. All these recent years, however, are well below the 1981-2010 30 year mean (more on this shortly).

This graph shows potential sea ice minimum extents for 2018 based on ice loss rates from previous years. 2018, through August 15, is shown in blue. Projections based on 2008 rates are shown in purple dots, and 2006 rates are shown in blue dots

This is a fascinating chart. Here's the NSIDC explanation:

"A simple way to project the upcoming annual minimum extent involves using the daily rates of change from previous years and applying them to the current sea ice extent. Following the 2005 to 2017 average rate of change between August 15 and the minimum, the extent is projected to drop to an annual low of 4.55 million square kilometers (1.76 million square miles), with a standard deviation range of 4.32 to 4.78 million square kilometers (1.67 to 1.85 million square miles). If sea ice extent continues at the rate of ice loss seen in 2008, the fastest recorded, the minimum at the end of summer would be 4.20 million square kilometers (1.62 million square miles), or the fourth lowest minimum in the satellite record. If sea ice extent continues with the rate for ice loss from 2006, the slowest recorded, the minimum would be 4.90 million square kilometers (1.89 million square miles), or the ninth lowest in the satellite record. It is possible that the rate of change through the remaining summer will be unprecedented in the satellite record (either faster or slower), yielding a final minimum extent outside of this range, but our estimates provide a window of the most likely minimum extent this year. Another possibility is that winds will consolidate the ice and reduce the overall extent. This was a factor contributing to the record low recorded in 2012."

So let's compare some of those highlighted years above by examining the March and September ice extent charts for each of those years (roughly the maximum and minimum ice extent levels for each year) and also go back much further. The satellite records that are reproduced by NSIDC started in 1979, so I'll cover some of those years initially and then use other records to go back further.

2016 had the second lowest ice minimum extent on record. Starting from quite close to the "decadal" average maximum in March, 2016 (with widespread local variations above and below average) 2016 saw the most rapid Spring ice melt on record and was running below the 2012 level up until July.

2012 saw by far the lowest minimum ice extent on record. Surprisingly, it started off with a maximum ice extent in March which was very close to the 1981-2010 30 year mean (the pink line in the chart) with above average ice extent in many parts cancelled out by well below average extent in the Barents and Kara Seas - something that we've seen become a standard feature of recent Arctic winters and can be focused on in another post in the coming weeks. 2012 only started running at the lowest ever extent from the beginning of July and saw amazingly rapid melting during July and August with additional melting right thru September. This was at least partly due to unusual weather patterns and again is something that we should examine much more closely on this thread as we need to understand which weather types and circulation patterns (+ any other factors) cause such rapid melting and which ones inhibit or slow down the melt rate.

I'm including 2008 as NSIDC in that prediction chart for the 2018 minimum rate compare it to that year which for the mid August period to early September had (for that short period) the fastest ever melt rate on record. Nevertheless, 2012 still ended up much lower with much later date for its minimum ice extent.

Now 2006, the year that saw the slowest ice melt from mid August to early September. It started off with slightly below average maximum extent in March (note: only slightly below in the Kara Sea) and ended up with slightly below average minimum extent.

1996 started with close to average maximum extent and following a very slow melt season ended up with one of the highest minimum extent in the satellite era second to 1980 - see below).

Although 1995 started off with slightly above average maximum extent it ended up with the lowest minimum at that time (similar to 1990) until the modern era from 2005 onwards.

1990 was very similar to 1995. Note that Newfoundland was almost completely engulfed in ice in March - something that we haven't seen since then. That isolated ice shelf east of Greenland was an interesting feature, separated and well beyond the 30 year mean line. I wonder if it broke off from the main ice sheet, rather like some of the activity we now see in Antarctica. I'll investigate.

1983 saw the second highest maximum ice extent in the satellite era.

1980 saw the greatest "annual average" extent in the satellite era. The maximum extent was only just shy of the 1983 second highest level. The minimum extent was the highest between 1979 and 2018.

1979 was the first year of the continuous satellite recording era. It saw the highest maximum ice extent, ahead of 1983 and 1980 while the minimum extent was the fourth highest in the modern satellite era.

NASA have a great animated chart (which I cannot copy as a gif image) which shows the ice sheet expanding and contracting from 1979 to 2015. I imagine that this animation has been updated to 2017 or even 2018. Here's the link: https://svs.gsfc.nasa.gov/4435

There are sporadic earlier satellite records from the 1960s such as the Nimbus 1 images which had been lost but were rediscovered in 2013. There are several papers and articles related to this and I'll place them in the Research Portal within a week or two. I will then write a short post to review those papers on here. In general, we have to rely on other data, records and estimations for earlier years (more details on this later). We need to be very careful here as some charts are produced to exaggerate the falling trend and a few attempt to smooth out the trend - the opposite ends of the global warming debate. The decline in sea ice extent is worrying enough without distorting the facts and figures or using confusing axis points and scales on graphs. I'll attempt to show what I believe to be the more realistic ones but even these show quite a diversity of values.

This chart shows the September (close to the annual minimum) ice extent from 1900 to 2016. In general terms the 1930s saw the lowest values in the 20th century until the late 1990s and were not that far above the 2000-2010 decade but well above the current decade. All the same, it does show that natural variability does produce quite significant changes and short term trends and also substantial year to year differences all of which we will need to examine on this thread. Minimum ice extent was much higher in the 1960s, with 1969 taking the record for the 20th century. My weather observing interests started in 1959. I read newspaper reports that the ice sheet in several 1960s winters practically reached the northern Iceland shores. In 1969 there were reports of ice bergs in the Norwegian and north North Sea and presenting shipping hazards down to the Scottish northern isles and several smaller ones being spotted off the northern mainland coast. These were truly exceptional conditions and probably the only example in the 20th century. Remember the Gulf Stream pushes warmer waters much further north in the eastern North Atlantic compared to the western North Atlantic.

Just to illustrate the problems with reconstructing earlier records, this chart shows the 1930s with September ice extent not quite so low as in the previous chart. Part of the problem is identifying sea ice concentrations, above or below the 15% threshold (that is used in the modern satellite era), open water and solid ice. I will go into more detail on how earlier records were constructed in the next part of this post. This chart does not include the 2014 onwards period. What it does reveal clearly is that until the current decade that winter maximum extent has fallen at a smaller rate than summer minimum extent (ie: re-freezing in the winter months should restore much or all of the ice lost in the previous melt season). In fact ice extent minimum values were double the recent values between 1850 and 1930, then became more variable, rising to the 1960s peak with the falling trend beginning in the 1970s and accelerating since 2000. The maximum extent does not really start falling significantly until after 2000. The axis and scale used on this chart are really as all the charts "should" be - from 0 to 20 in this case.

These sea ice concentration charts come from the same SIBT source. Both charts were part of the reconstruction work done jointly by NOAA and NSIDC. The extract below helps to explain how they gathered their data records and information:

"Gridded Monthly Arctic Sea Ice Back to 1850, for Analysis or Browsing

JULY 19, 2016

Until now, climate diagnostic applications, reanalyses, and atmospheric modeling studies that needed a lower boundary condition did not have an arctic-wide gridded ice concentration data set to use based on observations and one that extends back as far as the mid-nineteenth century. Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward addresses this need by improving and extending the Arctic and Southern Ocean Sea Ice Concentrations product. It does this by adding newly available historical sources and by using the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration for the satellite era.

Gridded ice concentration from regular aerial surveys of ice in the eastern arctic by the Arctic and Antarctic Research Institute, St. Petersburg, Russia, beginning in 1933.

Ice edge positions for Newfoundland and the Canadian Maritime Region from observations over the period 1870 through 1962.

Detailed charts of ice in the waters around Alaska for 1954 through 1978 called the The Dehn Collection of Arctic Sea Ice Charts, 1953-1986.

Arctic-wide maps of ice cover from the Danish Meteorological Institute over 1901-1956.

Whaling logbook entries noting ship position along with an indication of whether the ship was in the presence of ice.

The six sources already existed as data compilations in one form or another prior to our use of them, and with the exception of the Canadian ice edge positions and the whaling logbook data, these are available from the National Snow and Ice Data Center. However, some data sets, such as the Dehn collection, required digitization and interpretation before the information could be used. The documentation for Gridded Monthly Sea Ice Extent and Concentration, 1850 Onwardprovides references for all sources and details how each was prepared for processing. The data product is a NetCDF file covering January 1850 through December 2013. It will be updated and extended in 2017.

More information can be found in the July 2016 Geographical Review article cited below, and in a Cooperative Institute for Research in Environmental Sciences (CIRES) news article called Reconstructing Arctic History: Scientists build a new database to depict Arctic sea ice variations back to 1850. CIRES is a partnership of NOAA and CU-Boulder. The National Snow and Ice Data Center is part of CIRES.

Part of the reconstruction research, as shown above, was based on maps compiled by the Danish Meteorological Institute. Here's one from their archives:

it was produced in August 1926 and was compiled with information taken from shipping logs. There was far more "permanent" ice on the eastern side of the Arctic in late Summer back then compared to even "temporary" ice in late Winter now! The permanent ice sheet engulfed eastern Svalbard and stretched further south into the northern Barents Sea and all of the Kara Sea. The chart shows "tight pack ice" with a 70% to 90% concentration. We need to take into account the merits and accuracy of the 1926 chart. Of course they didn't have satellite imagery available and there were very few flights in that region back in those days. What was used were the highly accurate ship's log books. They kept meticulous records in those days. Many ships (and there were a lot more of them 90 years ago than there are today), particularly fishing trawlers, sailed right up to the edge of the main ice sheet as defined by the 70% to 90% "tight pack ice". The Danish Meteorological Institute explains the chart as follows:

..."The red symbols mark the location of observations recorded in ship logbooks. These are remarkable for their information value and because they represent a cooperative international effort to report ice conditions in a systematic way that was sustained over decades. These red symbols indicate the sea ice extent. “Tight pack-ice”, for example, indicates ice of 70% to 90% concentration of ice over the sea"...

There are a great many red symbols, especially on the Atlantic side of the Arctic - the most important in terms of ice loss in recent years. By analysing the readings and plots of the ice sheet edges, the Institute was able to put together a highly accurate map of the ice extent for the whole of the Arctic. There were also many coastal observations around the periphery. Perhaps the only slightly weaker area was towards the Bering Straits on the far side. If anything, the old method was even more reliable in terms of measuring the extent of the thicker (longer term) ice. Satellite images are restricted in terms of an overall picture but struggle to accurately show the detail of the thickness and depth of ice and areas of slightly broken ice. The sensory equipment only gives a fairly approximate reading. There are, of course, specialist expeditions and surveys carried out and several ice breakers take ice depth readings every year. Overall, the old method provided a highly accurate measure of ice extent.

The modern satellite era NSIDC charts show areas of the ocean with at least 15% sea ice extent. It is the permanent ice sheet extent which is most important and we should always make reference to sea ice concentration charts as well (as I did in my first Arctic report). Using the 1850 to 2012 graph (the previous chart above) I estimate that the September 1926 ice extent was about 8.25 million square kilometres. The current 15% ice extent is about 5.7 million square kilometres. I show the current sea ice concentration map below for a comparison.

So to compare like with like, we should be looking at the 70% to 90% (+) ice concentrations - that's the pale blue and white shades. I would estimate that it is close to half of the total ice (15% +) concentrations shown. So that would be equivalent to (5.7m x 50%) just 2.85 million square kilometers and only about 35% of the amount in August 1926.

Back to 1926 and from the 1850 to 2011 chart I would say that the March 1926 extent was about 16 million square kilometres. So, let's do the same comparison for March 2018 ice concentrations:

Most of the ice sheet is well concentrated and I would say about 80% is in the 70% + concentration band. So that would be (12.6m x 80%) 10.08 million square kilometers or around 60% of the March 1926 level. Overall, although this is based on various estimates and approximations, I feel that my calculations do help to provide a reasonable comparison between current conditions and those from 1926. I wonder if we can obtain more records, maps, charts and data from the Danish Meteorological Institute archives or from other sources for many other pre 1979 years. Records of ships logs go back to the 18th century.

Finally, one more chart:

This is one of those charts that uses a misleading axis and scale which exaggerates the trend. Yes, modern observations do show a very large and worrying falling trend and in fact, summer minimum extent levels have fallen much further since 2000 (below 4m in 2012 and nearer to 4.5m to 5m sq km in the last few summers) but to around 40% of the 1,450 year mean range (not falling to almost zero!). The reconstruction figures are mostly taken from ice core samples (and some ocean floor and other samples) and we must accept a high degree of approximation but the chart serves as a broad guide to the ice extent history.

Now that we have already produced quite a record of the ice extent facts and recent trends we need to start to examine the causes and review some of the excellent papers of various Arctic and Antarctica topics. I would also like to see posts on Greenland, glacial ice extent and global ice extent, so that we can assess the wider picture and net ice loss. It'll be great if a few more members can get involved on this thread. David

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Mountain Glaciers (1980–2017)

As you're planning a glacial ice extent post @Bring Back 1962-63 (David), I've posted this State of the Climate report here as well as in the Climate thread.

The longest-running records of glacier mass balance (whether a glacier loses or gains mass over the course of a year) are kept by the World Glacier Monitoring Service (WGMS). The group tracks changes in 140 glaciers; just over three dozen of them qualify as climate reference glaciers, with records spanning more than 30 years. In 2017, 29 of the reference glaciers were surveyed — including those from Austria, Canada, China, France, Italy, Kazakhstan, Norway, Russia, Switzerland, and the United States — and all but three showed a negative mass balance. Mass losses were especially dramatic in the European Alps.

Based on the preliminary data, 2017, is likely to be the 38th year in a row of mass loss of mountain glaciers worldwide. Furthermore, the melting of mountain glaciers has accelerated since 2000. According to the State of the Climate in 2017:

“The cumulative mass balance loss from 1980 to 2016 is -19.9 meters, the equivalent of cutting a 22-meter-thick (72-foot-thick) slice off the top of the average glacier."

The graph below shows the mass balance of 37 reference glaciers each year since 1980 (bars), along with the total mass loss over time (red line).

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I've just put a new paper into the Research Portal that makes for sobering reading. I've reproduced the abstract below:

Seasonal and Regional Manifestation of Arctic Sea Ice Loss

The Arctic Ocean is currently on a fast track toward seasonally ice-free conditions. Although most attention has been on the accelerating summer sea ice decline, large changes are also occurring in winter. This study assesses past, present, and possible future change in regional Northern Hemisphere sea ice extent throughout the year by examining sea ice concentration based on observations back to 1950, including the satellite record since 1979. At present, summer sea ice variability and change dominate in the perennial ice-covered Beaufort, Chukchi, East Siberian, Laptev, and Kara Seas, with the East Siberian Sea explaining the largest fraction of September ice loss (22%). Winter variability and change occur in the seasonally ice-covered seas farther south: the Barents Sea, Sea of Okhotsk, Greenland Sea, and Baffin Bay, with the Barents Sea carrying the largest fraction of loss in March (27%). The distinct regions of summer and winter sea ice variability and loss have generally been consistent since 1950, but appear at present to be in transformation as a result of the rapid ice loss in all seasons. As regions become seasonally ice free, future ice loss will be dominated by winter. The Kara Sea appears as the first currently perennial ice-covered sea to become ice free in September. Remaining on currently observed trends, the Arctic shelf seas are estimated to become seasonally ice free in the 2020s, and the seasonally ice-covered seas farther south to become ice free year-round from the 2050s.

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A very recent scientific paper (published Sept 24th 2018) and titled "C﻿ha﻿nging st﻿at﻿e of Arctic sea ice across all﻿ seas﻿on﻿s" provides some worrying quantification of the impact of warming in the Arctic. Here are some of the main conclusions:

Ice cover has not only retreated in its areal extent, it has also become much younger and thinner in recent years. In April 2018, only about 2% of the winter sea-ice cover consisted of sea ice older than 5 years, compared to almost 30% of the April sea-ice cover in 1984.

Accelerated sea ice loss during all months of the year is additionally driven by a lengthening of the melt season. As assessed for the Arctic as a whole through April 2018, melt onset is occurring 3 days earlier per decade, and freeze-up is happening 7 days later per decade. Over the 40 year long satellite record, this amounts to a 12 day earlier melt onset and a 28 day later freeze-up.

The primary cause of the ongoing changes in all months are anthropogenic CO2 emissions, with a clear linear relationship between sea ice loss and cumulative anthropogenic CO2 emissions in all months

Extrapolating the linear relationships into the future, we find that the Arctic Ocean completely loses its ice cover throughout August and September for an additional roughly 800 ± 300 Gt of anthropogenic CO2 emissions. For an additional 1400 ± 300 Gt of anthropogenic CO2 emissions, we estimate the Arctic to become sea-ice free from July throughout October.

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Every picture tells a story, and whilst the headline is that the Arctic Basin minimum Sea Ice Extent this fall is the 3rd lowest since records started in 1979, the graph highlights how the minimum level has been on a downward trend over the period 1979 - 2018. This from Zack Labe:

Sea ice extent is currently the third lowest on record for the inner Arctic Ocean basin. Each line is one year of @NSIDC daily data over the satellite era [purple (1979) to white (2017)]. 2018 is shown in red.